1. If a person looks at the sky at night, he won't be able to see the Milky Way by naked eye.

2. If noise pollution happens regularly, it will cause stress or nuisance.

3. If water pollution gets more serious in the future, it will affect the development of economy and society.

4. If Australian has invested in water in VN with good results, half of the population in the rural areas will have access to fresh water.

5. If you use compact light bulbs, you can save a lot of energy.

6. If we have more space, we will plant more trees.

V.

1. I would plant a lot of trees and flowers.

2. I would have a lot of money.

3. I would travel to Korea.

4. I would put garbage bins around the school yard.

5. I would went to the doctor the earliest.

IV/

1. If the person looks at the sky at night, he won't be able to see the Milky Wave by naked eyes.

2. If noise pollution happens regularly, it will cause stress or a nuisance.

3. If water pollution gets more serious in the future, it will affect the development of economy and society.

4. If Australia invests in water in VietNam with good results, half of the population in the rural area will access freshwater.

5. If you use compact light bulbs, you will save a lot of energy.

6. If we have more space, we will plant more trees.

V/

1. If I had a garden of my own, I would plant my favorite flowers.

2. If I had one wish, I would wish my parents lived longer.

3. If I won 1 million, I would give it to the charity fund.

4. If I were the principal,  I would organize a big cleaning festival for students and teachers to make our ground greener.

5. If I were infected with virus corona, I would go to the hospital, keep hygiene and isolate myself.